One girl's salt is another girl's fleur de sel

May 15, 2011

Gluten-free pasta doesn't have to suck: a simple kitchen trick that will blow you away

I've been eating brown rice pasta since this blog was founded about 5 years ago. And I've always liked it. Not as much as I like the chewy, toothsome texture of wheat pasta, but I find that if I drowned it in enough sauce, I can fool almost anyone. Except when I reheat it.* There is no mistaking the gummy texture of reheated rice pasta. But I recently discovered a trick that significantly improves the texture, performance, and speed of cooking of brown rice pasta. And allows reheating (though microwave cooking more than a few seconds will still gum it up a bit). And I learned it from a book.

By chance, The other day during a long plane ride I read the remarkably enjoyable and enlightening book, Ideas in Food, the print version of the much loved pro-chef blog, Ideas in Food by Aki Kamozawa and H. Alexander Talbot. If you love to cook and haven't read this book, I can't recommend it enough. Although many of the insights are around techniques and concepts that may be alien to some home cooks, their advice and insight is inspiring and may get you to try out things you'd otherwise not consider.

One simple idea from their book has completely changed the way I prepare brown rice pasta. On page 116 of their book, (or, in fewer details, this page on their blog), Talbot and Kamozawa explain how to quickly cook pasta - cutting cooking time in half, if not more - by soaking pasta in cold water for 1-2 hours before cooking (they hold the hydtrating pasta and water in a Ziploc-type bag). The hydrated pasta can then be stored in the refrigerator for up to 3 days. The pasta can then be quickly cooked in boiling water for 1-5 minutes, depending on the duration of the soak. It is a great trick for restaurants, which often par-cook their pasta before service with mixed results. Pre-hydrated pasta cooks up fresh and chewy, and the long soak in cold water prevents sticking in the water and reduces sticking during storage, so less boiling water is needed to get perfect pasta. Think of the pot of water you boil for a pasta dinner, now imagine that water reduced by more than half. The time required to boil that smaller pot is significantly less than that large pot of water. Voila, you just got a few hours of your life back.

Talbot and Kamozawa then make the hydration even more compelling by introducing a flavorful soaking liquid. They tried out mushroom stock and clam broth as the soaking medium for the pasta, and both yeilded excellent results. They also found that they could roast it in the oven prior to soaking, and that leaving dry pasta for a two-hour stint in the smoker resulted in a savory, flavorful finished dish.

So how does a chapter and a blog post on wheat pasta translate into meaningful gluten-free food prep?

Well, what applies to wheat also applies to rice, with some modifications.

Wheat hydrates much more quickly than rice does, by a factor of about .5, or 50% more quickly. So rice pasta needs a longer soak to reduce cooking time. Wheat doesn't mush up quite as much as rice does, so rice requires a second cold water rinse after cooking. But for spaghettis made of either grain, a one hour hydration vastly improves the texture of pasta. And the cold water soak helps reduce the amount of starch on the surface of the pasta, making it much less sticky as it cooks.

After a one hour soak, spaghetti-style rice pasta is slightly more flexible than raw pasta but still brittle. Cooking to al dente at this point reduces boiling time from 15 minutes to 4 minutes, and only a small fraction of the water recommended by the manufacturer is needed. After 1.5 hours, the pasta was much softer and flexible though it broke when bent. After two hours, the spaghetti could be bent without breaking. It was al dente, though I'd not want to eat it raw. At 2.5 hours, the pasta is al dente and is extremely flexible, but it cooks almost too fast and gets mushy quickly. All of the pastas, once drained and sealed in a Ziploc-type bag and refrigerated continued to soften as the water migrated to the dryer center of the pasta strand. The softening was perceptible in the raw pasta but did not negatively impact the finished texture.

I prefered the 1 hour or 1.5 hour soak over the hydrating soaks of longer duration. Even though 1-1.5 hour soaks required a longer cook time, it was easier to control the cooking time and texture and the pasta was slightly less sticky. I fed the results to a friend and he agreed that the al dente pieces reminded him more of the wheat pasta and that the gummier mushy pasta was definitely not like wheat pasta at all.

Once the pasta is cooked and cooled in cold water, it can be wrapped in an airtight container or bag and stored in the refrigerator up to three days and reheated. The results will be excellent.

Other pasta shapes - penne, macaroni, rigatoni, sprials - will require more hydration time. Two hours is usually enough.

My takeaway is that any amount of hydration will improve cooking time. Even if you can only hydrate the pasta while you wait for your pasta water to heat up, you will reduce your cooking time.

Can hydration be accelerated? I don't like sticky pasta, though. What else can I do?

Well, there's not a ton you can do about stickiness. Rice pasta is rice pasta, though as you'll see below, you can do a few things that will help it become the best pasta it can be given its inherent limitations.

I decided to try out another technique to see if I could further improve the process without affecting texture. I had read in Ideas in Food about the par-cooking of rice for risotto. They explain how starch absorbs water thusly:

"When we cook rice or potatoes in hot water, the starch granules soak up the water and swell to the point of bursting, or gelatinize. The more water is absorbed, the lower the gelantinization temperature. If the starch does not cook long enough to absorb enough water, it will not completely gelatinize."

-Talbot and Kamozawa, Ideas in Food, page 120

One of the problems with rice-based pastas is they get gummy fast, that is, rice pasta gels and gets sticky when cooked because the cell walls of the starch (mostly amylopectin, with a low but appreciable amount of amylose) burst when cooked. If a starch can undergo retrogradation (a process that is responsible for the staling of bread but also the reinforcement of starch cell walls, a good thing for rice pasta and potatoes), some of this sticky/gummy texture can be remedied. But rice is generally low in amylose, one of the keys in retrogradation. The amylopectin fraction of rice starch forms crystals as it cools that melt as it is heated up. Anyone who has eaten cold rice before reheating it has experienced this. Rice pasta is similarly grainy when cold.

Rice pasta, however, is not rice. Unlike rice, rice pasta is heat-extruded and dried, meaning its chemical composition is quite different from that of dried rice. According to this study from Cereal Science (published in 2000), heated and extruded pasta that is cooked and then kept in refrigeration will undergo rapid but low levels of retrogradation - meaning that stickiness cannot be completely eliminated from rice pasta but that it can be reduced to a minor but perceptible extent.

But here's the good news: you can both speed up the hydration of the pasta AND (mostly? somewhat?) conquer stickiness with a process that's a little fussy but not difficult.

METHOD

Rice gelantinizes at 150-170 degrees, depending on the type of rice used. I don't know what kind of rice is used in brown rice pasta, but I assumed that because the starch molecule was damaged in heating and extruding, the gelatinization temperature should be lower. If rice pasta is cooked somewhere around that temperature, I reasoned, maybe I could use retrogradation to my advantage by gelatinizing the starch without bursting the molecule.

I heated water on the stove to 155F. I put the uncooked dry rice pasta in the 155F water for 20 minutes, until it was soft. I immediately plunged it in cold water to chill it down completely. At this point the pasta could have been refrigerated up to three days. I then boiled water and put the par-cooked pasta in for 30 seconds. That's right. 30 seconds. I then drained it and plunged it into cold water. I put it in a bag and put that bag in the refrigerator and checked it every five minutes.

And guess what?

The pasta wasn't sticky at all. It didn't stick to my hands or to itself. It was a little tacky, but significantly less than it does from a straight boil or even from the pre-hydration method. Of course it still got a little crunchy and sticky over time in the refrigerator, but not to the extent I had experienced before. And the texture was much more toothsome and - dare I say it - similar to wheat pasta.

And it tasted really good.

Here's the summary of what I did:

Parcook pasta 20 mins in 155F salted water > chill down in cold water and drain > Boil for 30 seconds > Chill in cold water and drain > use immediately OR refrigerate up to 3 days

Buckwheat Soba

I wondered how the soak would affect buckwheat pasata, or Soba. I love soba - it is easily one of my favorite noodles. I've almost never liked the ubiquitous-in-the-US dry soba as the texture never seemed quite right to me. From time to time I've purchased fresh frozen soba noodles, but they're expensive and available only at specialty markets. By contrast, dry soba is available almost anywhere that has an international section with Japanese or Korean ingredients, including Whole Foods. Not all soba is 100% buckwheat, so read the label carefully before purchasing or you may inadvertently glutenize yourself.

I soaked the (Roland Brand, purchased at Whole Foods) buckwheat soba in cold water and checked it every five minutes. Because it is thin and fine, and buckwheat is highly water absorbent, after twenty minutes it was soft and hydrated. If broken, it looked al dente. I was worried it would be sticky, as cooked dry soba often is. I rinsed it just before plunging it into boiling water and cooked it for 1 minute. I removed it from the water, gave it a quick cold-water rinse and tasted it.

It was the best dried soba I'd ever tasted - it had the texture of fresh soba. It was chewy and tender. It wasn't mushy or sticky. It was perfect.

So you think you want to try this out

Of course, you do need to prepare ahead to use this technique. Hydrating pasta takes at least an hour to rinse of the sticky surface starches and accelerate cooking time - so planning is a must. If you hydrate your pasta as you prepare the rest of your meal, and save cooking the pasta until the end, you can use the technique at meal time. Because you can hold the hydrated pasta up to three days, a meal planned in advance can be simplified with the technique. The technique is passive and the hydrating pasta only needs attention when it needs to be removed from the water it is soaking in. The pasta will disintegrate if hydrated for too long. You'll need to hydrate larger pasta shapes longer - every pasta type is different.

There's a bunch of food science behind why this works, but I'm no food scientist and any attempt I make to explain it will fall short. If you're really interested in rice science and food tech, you can always read this book.

In any case, pre-hydrating your gluten-free pasta will improve it. Even if it is just the time it takes to prepare and serve it. And if you try the flavorful hydration liquid, you'll make it far more interesting than you ever imagined it could be.

*Note on reheating: if you use a microwave to reheat your pasta, I don't care how it's been pre-hydrated, it will always turn out gummy because of the rice flour. To avoid gummy, sticky, mushy and dissolving pasta, reheat your cooked pasta either in hot water, sauce heated up in a pan, or, if already sauced, gently in a covered sauce pan, stirring and checking as you reheat it. Once it starts gumming up, there's no going back. Such is the danger of high temp high heat reheating of rice-based pasta.

3 Comments

I don't know if you keep this up anymore - blogs do inevitably decay - but I've just cooked a package of brown rice linguine for 4 and a half minutes after soaking for 90 and ended up with the first genuinely good rice pasta dish I've cooked. The texture was GOOD, not just bearable.

Thank you for this, it's one of the most genuinely helpful cooking posts I've ever read.

This is an absolutely fascinating post! I will absolutely try hydration and flavourful soak liquids so I can finally return to making large pasta dishes and having lots left over. Much obliged for your excellent work.